Elastic fluid generator



' Dec. 22, 1942. K QKANIWA` 2,306,183

ELASTIC FLUID GENERATOR Filed oet. 23, 1940 Inventor: Keji Okaniwa,

Patented Dec. 22, 1942 ELASTEC' FLUID GENERATR Heji Okaniwa, Yokohama, Japan, assignor to General Electric Company, a corporation of New York repentance october ze, 1941i, serial No. 362,391 In llapan January 17, 1940 l Claim. (Cl. 122-444) The present invention relates to elastic iiuid 2l. The elastic huid is discharged from the drum generators or boilers, particularly to steam boil- 2i through a superheater 25 located in the coners with an economizer to preheat feed water or vection chamber I3 and having an inlet conduit like operating liquid for the boiler. 26 connected to the vapor space of the drum and An object of my invention is to provide an im- 5 a discharge conduit 21 for connection to a conproved construction and arrangement of boilers sumer of elastic fluid. whereby a maximum amount of available heat Feed water or like operating liquid is supplied energy in the combustion gases is utilized to preto the drum from a source, not shown, through heat and evaporate huid in the economizer. a feed pump 23 and an economizer located in the Another object of my invention is to provide an io convection chamber I4 and connected between improved economizer whereby oxidation and scale the pump 23 and the drum 2i. formation in the heating tubes are reduced to a The economizer in accordance with my invenminimum. tion comprises a first section 29 located near the For a consideration of what I believe to be novel stack I 6, that is, near the outlet of the convecand my invention, attention is directed to the l5 tion chamber It, and a second section 30 located following description and the claim appended near the inlet of the convection chamber I4 and thereto in connection with the accompanying connected in series between the section 29 and the drawing. drum 2|. The section 29 of the economizer com- In the drawing, Fig. 1 illustrates diagrammatiprises a plurality Of parallel Connected banks 0f cally a sectional view of a boiler embodying my tubes 3l, 32 with each tube having a plurality of invention, and Fig. 2 is a section along lines 2 2 hairpin-shaped series-connected portions of relaof Fig. 1. tively large diameter and outer finned surfaces. The arrangement comprises walls id and H The tubes of the first section 29rare made of castv formingacombustion chamber l2 and convection 11011- They are 0f large diameter and ClOSelS7 chambers i3 and it. Fuel and combustion air 25 Spaoed and, therefore, effect 10W VelOCity 0f the are conducted to the combustion chamber by Water through the tubes and comparatively high means including a burner l5 suitably supported Velocity of the combustion gases through the on and projecting into the chamber l2. During Spaces formed between the tubes.

operation, combustion gases formed in the cham- The second economzer section 35 also consists ber l2 are discharged therefrom through the 30 of a plurality of parallel connected tubes 33, each series-connected convection chambers I3 and lll. having a plurality 0f series-connected hairpin- The gases i the last convection chamber it are Shaped tube portions. The tubes 33 are made of discharged to atmosphere through a stack it con- Steel and are of small inner diameter as compared nected to the lower end ef the chamber it. t0 the inner diameter of the tubes el, s2. in ad- The boiler proper comprises banks of slanted 31 dtOll, the tubes 33 are comparatively Widely heating tubes I1 having inlet portions located in SpaCed. Hence, the Water OI miXtllre 0f liquid the convection chamber i12 and connected to a and steam is forced through the tubes 33 at high header I8 and outlet portions located in the upper velocity Whereas the Combustion gases DaSS part of the combustion chamber l 2 and connected through the Spaces OI'lhed between the tubes 33 to an outlet header le. Water er like operating 40 at comparatively 10W velocity. liquid is conducted to the inlet header I8 by a plu- The economizer'is of the evaporation type, that rality of down-tubes 2c lining the wall l l and hav- S, a Dart 0f the liquid iS eVapOrated in the second ing upper ends Connected to the bottom portion economizer section 29, the mixture of liquid and of a drum 2l. The liquid, on its path through vapor being discharged into the vapor space of the tubes I7, is heated and partly evaporated, and 15 lhe drum 2 l FlOm the latter, the Vapor is passed the mixture is discharged from the outlet header through the superheater 25, whereas the liquid i9 through a plurality of up-tubes 22 lining anis passed through the liquid heating and evapoother portion of the Wall H and connected to the rating tllheS 20, il, and 22.

vapor space of the drum 2l. An upper row of the During operation of the boiler, Scale-fOrml'ng tubes I7 has portions 23 bent upwardly and ar- 50 ingredients carried in the feed Water discharged ranged to line a partition 2a between the convecfrom the pump 28 are decomposed and precipition chambers i3 and lll. The upper ends of the tated in the first economizer section 2S and, at tube portions 23 are connected to the aforementhe same time, oxygen contained in the feed water tioned tubes 22 to discharge the mixture of liquid is absorbed on the inner surface of the cast iron and vapor formed in the tubes 23 into the drum 55 heating tubes 3l, 32 0f the rst section. High 2 velocity of circulating Water in the second economizer section together with the function of the first economizer section reduces oxidation and scale formation on the evaporating tubes of the second economizer section 29.

What I claim as new and desire to secure by Letters Patent of the United States is:

An elastic fluid generator comprising walls forming a combustion chamber and a convection chamber located adjacent the combustion chamber and having an end connected thereto to receive gases discharged from the combustion chamber, a drum, combustion chamber and partly in the convection chamber and connected to the drum and means including an economizer for supplying preheated fluid to the drum, the economizer having a first heating tubes located partly in the section located near the outlet of the convection chamber on one side of the heating tubes and comprising a bank of closely spaced cast iron heating tubes of wide diameter and a. second section near the inlet of the convection chamber on the other side of the heating tubes and connected in series between the first section and the drum and comprising a bank of Widely spaced steel tubes of small diameter to effect 10W velocity of the combustion gases through the spaces formed by the second section and high gas velocity through the spaces formed by the flrst section and also to eiect low velocity of the operating uid through the first section and high velocity of the operating uid through the second section.

KEIJI OKANIWA. 

